Short Answer

Sometimes. A consulting arborist may be able to determine whether a fallen tree had defects, damage, decay, structural problems, root issues, or other conditions that increased the likelihood of failure before the incident occurred. The strength of that opinion depends on the physical evidence, photographs, records, site conditions, maintenance history, and other information that remains available. A tree's failure does not automatically mean that it was obviously dangerous beforehand.

What Does an Arborist Look for After a Tree Fails?

A tree failure investigation begins with the evidence that is still available.

Depending on the circumstances, an arborist may examine:

• The remaining stump

• Roots and root plate

• Trunk and branches

• The point where the failure occurred

• Decay or cavities

• Cracks or splits

• Previous wounds

• Dead or weakened wood

• Branch attachments

• Previous pruning

• Soil and site conditions

• Construction or excavation near the tree

• Photographs taken before the failure

• Tree maintenance or inspection records

• Weather conditions at the time of failure

The purpose is to understand both how the tree failed and what conditions may have existed before the failure occurred.

Does a Fallen Tree Mean It Was Hazardous Before It Fell?

No.

The fact that a tree fell does not, by itself, establish that the tree was obviously hazardous beforehand.

Trees are living structures, and failures can occur for many reasons. Severe weather, hidden decay, root problems, structural defects, previous damage, soil conditions, or a combination of factors may contribute to a failure.

Some defects are readily visible. Others can be difficult to detect without a more detailed assessment.

An arborist should evaluate the available evidence rather than assume that the outcome of the failure proves what someone should have known beforehand.

What Types of Defects May Increase the Risk of Tree Failure?

Different defects may be significant depending on the tree, location, severity of the condition, and surrounding circumstances.

Potential concerns may include:

• Significant decay

• Cavities

• Cracks

• Weak branch attachments

• Dead or dying branches

• Root decay

• Root cutting or damage

• Previous partial failures

• Severe structural imbalance

• Trunk wounds

• Excessive lean in certain circumstances

• Soil instability

• Construction-related damage

• Significant changes around the root system

The presence of a defect does not automatically mean a tree was likely to fail.

The arborist must consider the significance of the condition in the context of the entire tree and site.

Can a Tree Look Healthy and Still Have a Serious Problem?

Yes.

A tree may have a full canopy and appear healthy while still having a structural problem.

Tree health and tree structural stability are related, but they are not the same thing.

For example, significant decay or root damage may sometimes exist while portions of the tree continue to produce normal foliage.

That is one reason evaluating tree risk requires more than simply deciding whether a tree looks green and healthy.

Can an Arborist Tell Whether a Defect Was Visible Before the Failure?

Sometimes.

This question may be especially important when a dispute involves whether a tree owner, manager, contractor, or other party could reasonably have recognized a potential problem.

An arborist may consider:

• The type of defect

• Its location

• Its apparent age or development

• Whether it was externally visible

• Whether earlier photographs show the condition

• Whether previous inspections documented it

• Whether symptoms were present elsewhere in the tree

• Whether specialized testing would have been needed to detect it

A condition that becomes obvious after a tree breaks apart may not necessarily have been obvious beforehand.

What If the Problem Was Hidden Inside the Tree?

Internal decay and other concealed conditions can make tree-failure investigations more complicated.

When a tree fails, the newly exposed wood may reveal conditions that were not visible while the tree was standing.

An arborist may evaluate whether there were external indicators that could have suggested a hidden problem before the failure.

In some cases there may have been signs worth investigating. In others, little or no outward evidence may have been present.

The answer depends on the particular tree and the evidence available.

Can Root Problems Cause a Tree to Fall?

Yes.

Roots play a critical role in both tree health and structural stability.

Potential root-related issues may include:

• Root decay

• Root cutting

• Excavation

• Trenching

• Soil compaction

• Grade changes

• Construction activity

• Changes in drainage

• Restricted rooting space

• Damage from equipment

Because roots are largely underground, significant problems are not always immediately apparent from looking at the trunk and canopy.

When a tree uproots or fails near the base, examining the root system and surrounding soil conditions may provide important information.

Can Construction Make a Tree More Likely to Fail Later?

Yes.

Construction activity can affect trees in ways that may not become obvious immediately.

Possible impacts include:

• Cutting structural roots

• Compacting soil

• Excavating near the tree

• Changing soil grade

• Altering drainage

• Damaging the trunk

• Removing nearby trees

• Changing wind exposure

• Restricting the root zone

A tree may continue living after construction damage while becoming progressively weakened.

When a failure occurs following construction or major changes to the surrounding property, an arborist may investigate whether those activities contributed to the tree's condition.

Does Previous Pruning Matter?

It can.

Previous pruning may affect tree structure depending on what was removed and how the work was performed.

An arborist may examine:

• Old pruning cuts

• Large limbs that were removed

• Changes in canopy balance

• Topping or excessive pruning

• Damaged branch attachments

• Wounds associated with previous work

• Records showing when work occurred

Proper pruning can help manage tree structure, while inappropriate work may sometimes create or worsen problems.

The significance of previous pruning must be evaluated in the context of the particular tree.

Does a Storm Mean the Tree Was Not Dangerous Beforehand?

Not necessarily.

Severe weather can cause even relatively sound trees to fail.

At the same time, wind, rain, or saturated soil may expose weaknesses that were already present.

An arborist may therefore consider both:

• The severity of the weather event

• The pre-existing condition of the tree

The relevant question may be whether weather alone reasonably explains the failure or whether significant tree-related conditions also contributed.

Can Old Photographs Help Determine the Tree's Prior Condition?

Yes.

Photographs taken before a failure can sometimes provide valuable evidence.

They may show:

• Dead branches

• Canopy condition

• Lean

• Previous failures

• Pruning

• Construction around the tree

• Changes to neighboring trees

• Visible wounds or cavities

• Changes in the surrounding property

Even photographs that were not originally taken to document the tree can sometimes provide useful historical information.

Why Are Tree Inspection Records Important?

Inspection and maintenance records may help establish what was previously observed about a tree.

Potential records may include:

• Arborist reports

• Tree risk assessments

• Tree-company recommendations

• Pruning records

• Removal recommendations

• Work orders

• Treatment records

• Communications concerning the tree

These records may help establish whether concerns were previously identified and what action, if any, was recommended or performed.

Their significance depends on the circumstances of the individual case.

What If the Tree Was Never Professionally Inspected?

A lack of professional inspection does not by itself answer whether someone was legally responsible for a later failure.

An arborist may still evaluate the physical evidence, photographs, property conditions, witness information, and other available materials.

Questions about what inspections were legally required or what a property owner should have done involve legal standards that should be addressed by the appropriate legal professionals.

The arborist's role is to explain the tree-related conditions and professional arboricultural issues.

Can an Arborist Determine Exactly When a Defect Developed?

Not always.

Some tree conditions develop gradually over many years, while others result from a specific event.

An arborist may sometimes be able to provide information about the development or history of a defect, but the available evidence may not support an exact date.

A sound expert opinion should recognize these limitations rather than claim a level of certainty that the evidence does not support.

Why Is Preserving the Fallen Tree Important?

A fallen tree may contain some of the most important evidence in a tree-failure investigation.

Once the tree is:

• Cut apart

• Chipped

• Hauled away

• Burned

• Disposed of

• Or the stump is ground

important evidence may be permanently lost.

When a tree failure results in serious injury, substantial property damage, an insurance dispute, or potential litigation, it may be useful to determine whether an arborist should inspect the tree before cleanup is completed.

Safety should always come first, but photographs and documentation should be preserved whenever practical.

Can an Arborist Determine Whether Someone Should Have Known the Tree Was Dangerous?

An arborist may provide professional opinions concerning the tree's condition, whether significant indicators were present, and whether those indicators could reasonably have been detected through an appropriate arboricultural evaluation.

However, determining whether a particular person was legally negligent or had a legal duty to take action is a separate legal question.

The arborist provides the technical tree-related findings.

Attorneys, insurers, courts, and other appropriate decision-makers can then consider those findings together with the applicable legal standards.

When Should an Arborist Be Contacted After a Tree Failure?

Consider contacting a consulting arborist promptly when a tree failure involves:

• Personal injury

• Significant property damage

• An insurance dispute

• Questions about negligence

• A disagreement between neighboring property owners

• Construction-related tree damage

• Questions about prior tree condition

• Potential litigation

Early involvement can allow the arborist to examine evidence before the site changes.

About Marty Shaw, RCA

Marty Shaw, RCA is a consulting arborist, investigator, tree and plant appraiser, author, and expert witness with decades of experience addressing complex tree matters.

His work includes tree failure investigations, tree risk assessment, property disputes, construction-related tree damage, insurance matters, appraisal, and litigation involving trees and landscapes.

Green Season Consulting provides independent arboricultural expertise for attorneys, insurance professionals, property owners, organizations, and others who need professional analysis of difficult tree-related questions.

Contact Marty Shaw About a Case:

Email: expert@greenseasonconsulting.com. Call: (615) 794-4377

This information is provided for general educational purposes and is not legal advice. Questions involving negligence, liability, ownership, damages, or other legal rights should be discussed with a qualified attorney.